Intermediate data rate (IDR) implementation examples

Various example earth-station equipment configurations for IDR implementation are provided. These include FDM/FM to IDR conversion, single destination IDR operation and multi-destination IDR operation.     

快速响应矩阵码纠错算法的研究

在研究纠错技术的基础上，采用高级语言，实现了快速响应矩阵码中基于伽罗华域GF（28）的Reed-Solomon编码和译码算法.在编码部分提出对国际标准中生成多项式的个数进行了压缩，有效实现各版本的生成多项式：对较大版本采用交错码技术，将错误离散，提高突发错误的纠正能力.实验表明，本算法实现了高效的纠错编码和译码。     

Transmission of intermediate data rates: The mercury experience

Mercury Communications Limited was granted a telecommunications licence at a time when INTELSAT was beginning to introduce transmission methods using intermediate data rates. As a new operator with no existing earth-stations, Mercury took the opportunity to procure equipment which would comply with the latest specifications for digital services. This paper describes the various operational needs and engineering design considerations that were necessary in order for earth-station equipment to meet the requirements.     

Depolarization properties of metal space frame radomes for use in satellite communication systems

Radomes have traditionally only been used in military satellite systems. However, higher availability civil applications are demanding their consideration in the higher frequency bands and for dualpolarization frequency re-use systems. This paper investigates the depolarization performance of metal space frame radomes and presents results of XPD for radome covered antennas in the 4/6 and 11/14 GHz bands and for antennas of 30, 11, 5 and 3 m diameters. It is demonstrated that current polarization specifications adopted in the INTELSAT system should be able to be met by radome covered earth-stations using conventional antennas.     

Ku-band satellite digital transmission systems

A nation-wide data communications service is being placed in service by a major telecommunications carrier. This service will rely on a satellite network being provided and installed by Harris Satellite Communications Corporation. The network supports information data rates from 56 kb/s to 2·048 Mb/s. This data communications network has been architectured to include a number of innovative monitor and control functions, up-link power control, modular equipment shelter design and a modular antenna/feed subsystem. This paper will detail this application.     

VSATS in Japan

In Japan, private domestic communications satellites, JCSAT and SuperBird, carrying K_u-band transponders, were launched in 1989, and the use of the VSATs started. To expedite a wider use of the VSAT systems, regulations were amended in June 1989 to permit simplified licensing procedures for the VSATs which conformed to technical standards. This contribution describes the usage of VSAT systems in Japan along with the licensing procedures and the technical standards.     

Ku波段上变频组件的设计

介绍了Ku波段上变频组件的设计与制作,整个组件由低相噪振荡器、滤波器、功分器、功率放大器、PIN开关、上变频器等部分组成。文章分别对一些主要部件进行了简要的理论分析,并给出微波电路的结构形式,最后给出样品的测试结果。     

Ku波段电调衰减器模块研究

采用混合集成电路的方法,用并联PIN二极管芯片在很小的腔体内制作广Ku波段吸收式电调衰减器。动态范围大于20dB,电压驻波比小于1．4,插入损耗小于0．85dB,相应变化（插入态／衰减态）小于等于2．7°,传输时间小于100ns,线性度优于10％．驱动电流DC5mA、模块体积9mm（L）×7．6mm（W）×4mm（H）。     

Pointing losses in single-axis and fixed-mount earth-station antennas due to satellite movement

There are substantial cost advantages in the use of single-axis or fixed-mount earth-station antennas, thus reducing or eliminating the need for autotracking in earth-stations operating with quasi-stationary satellites. Such cost advantages are more relevant in small antennas where the tracking system represents a larger percentage of the overall cost. In addition, small antennas are particularly suitable to be operated without autotracking, owing to their wider half-power beamwidth. This paper describes a model for calculating the antenna pointing loss as a function of the antenna diameter, operating frequency band, satellite station-keeping tolerances, and the relative geometry between the earth-station and the satellite. The model has been extensively used in the development of INTELSAT's IBS and VISTA services as well as in domestic leases. Although the model has been developed based on orbital mechanics equations, its emphasis is towards earth-station and systems engineering applications. Some example calculations and results obtained through an HP-41 CV programmable calculator are also provided.     

浅海水声信道中原模图LDPC码的设计及性能分析

原模图低密度奇偶校验码相较于传统LDPC码,具有结构简单、迭代译码门限低、易于扩展及线性编译码复杂度等优点。针对强多途、长时延、窄带宽的浅海水声信道,该文研究了PG-LDPC码的设计及性能特征,提出一种码型设计方案,并采用基于原模图度分布的外部信息转移图算法,对所设计PG-LDPC码的纠错性能进行分析及预测。仿真与实验结果表明,与(3,6)随机规则LDPC码相比,所提的PG-LDPC码在低、高信噪比区域均有良好的纠错性能。     

Ku频段上变频器的设计与实现

阐述了一种Ku频段卫星通信上变频器的实现方案,针对低杂散和低相位噪声输出这2个难点,采用多次变频方案以及选用高抑制度的滤波器实现变频器的低杂散输出;采用多环锁相方案实现低相位噪声输出。给出测试结果,杂散抑制-70dBc(500MHz带内),相位噪声-85dBc/Hz@10kHz,验证了该方案的可行性。     

一种Ku波段固态发射机的设计

介绍一种Ku波段固态发射机的设计,本发射机是脉冲工作,采用了功率合成,输出脉冲功率45w,工作比为20％.     

有STC控制的Ku波段接收组件研究

本文介绍了有STC控制的Ku波段接收组件的研究工作，该接收组件包含多个功能单元，有PIN电调衰减，低噪声放大器，镜频抑制混频器，前置中频放大器，STC控制电路等，介绍了组件整体和各功能电路的设计理论，设计考虑，设计结果等。     

舰载Ku波段卫星通信雨衰分析及解决措施

雨衰是影响Ku波段卫星通信系统传输质量及系统性能的主要因素之一.本文介绍了Ku波段卫星通信中雨衰产生的机理及其对卫星信道的影响,并提出了有效减少雨衰对Ku波段卫星通信不利影响的策略.     

Ku波段模拟预失真线性化器

提出了一种基于模拟预失真方法的线性化器设计。利用预失真技术设计行波管配用线性化器的数学模型,得出了预失真电路的功率转移特性曲线和相位特性曲线。预失真电路采用上下支路对消结构,通过二极管产生失真信号,并利用2个可调衰减器和可调移相器来调节其幅度和相位,以此补偿功率放大器的AM-AM,AM-PM失真特性,改善输出信号的线性度。此外通过改变二极管的偏压,线性化器能够提供不同种幅度和相位特性的组合方式,用于不同特性的功放。基于该模拟预失真方法设计了行波管线性化器,在给定的动态范围内幅度扩张5 dB,相位扩张40°。     

基于GEMS对Ku波段螺旋阵列天线的设计优化

详细阐述平面螺旋天线阵列,利用其具有效率高、旁瓣低和受环境等影响小等优点改善其整体性能。选择小螺旋作为Ku波段的螺旋阵列天线的辐射阵元,利用基于FDTD算法的GEMS软件仿真,调节螺旋参数满足天线设计指标,借助仿真结果确定天线阵列的几何参数,并对其进行测试。通过调试得到优化的结果,基于仿真结果与实测结果进行分析加工和重设计,以组成更大的天线阵列,满足实际需要。     

一种用于Ku波段通信的双极化微带贴片天线的单元设计

运用口径耦合的馈电方式及叠层贴片形式设计出一种新型的用于Ku波段通信的双极化微带贴片天线。给出单元天线的结构及设计方法,同时探讨了各项参数对天线性能的影响。测试结果表明,单元天线端口驻波比小于2(VSWR<2)的相对带宽达到20.5%和23.7%,单元的极化隔离度低于-36.5 dB,理论计算结果与实测值一致。     

隔离度大于95dB的Ku波段微带型开关

研究了具备高隔离度性能的Ku波段基于PIN二极管的微带型开关电路,通过采用含有多个子单元电路的拓扑结构以及合理优化子单元电路参数,解决了微带型开关在微波频段难以实现高隔离度的难题.所研制的开关电路在15.75～16.25GHz频段范围内.隔离度大于95dB,插入损耗小于4dB,输入端S11均小于-12dB,输出端S22均小于-20dB,电路体积仪为34mmX 11mm×5mm.     

隔离度大于95dB的Ku波段微带型开关

研究了具备高隔离度性能的Ku 波段基于PIN 二极管的微带型开关电路,通过采用含有多个子单元电路的拓扑结构以及合理优化子单元电路参数,解决了微带型开关在微波频段难以实现高隔离度的难题. 所研制的开关电路在15.75~16.25GHz频段范围内,隔离度大于95dB,插入损耗小于4dB,输入端S11均小于-12dB,输出端S22均小于-20dB, 电路体积仅为34mm×11mm×5mm.     

Ku波段频率合成器

为了达到频率综合在具有高频率稳定度、低杂散信号、高隔离度等特点的同时,尽可能实现产品的小型化这一目的,通过分析多种方案的特点和理论计算,最终选出了一种最优方案,并在科研制造中得到了验证。介绍了频率合成技术的基础理论,着重研究了PLL＋DDS的频率合成技术,并简述了实现Ku波段频率合成的主要技术途径,给出了主要技术难点、解决措施。